Docosahexaenoic acid (DHA) during pregnancy improves infant health

A recent study completed at Emory University and funded by the National Institute of Health, USA and the March of Dimes Foundation charity, has confirmed a preliminary finding that DHA supplementation during pregnancy improves infant’s immune function as measured by frequency and intensity of illness symptoms.

The randomized, double-blind, placebo-controlled clinical trial included 1094 pregnant women who took either 400 mg of algal sourced DHA or a placebo daily from 18-22 weeks’ gestation through parturition. Their infants were assessed at ages 1 (n=849), 3 (n=834) and 6 (n= 834) months for the occurrence and duration of a variety of common illness symptoms in the preceding 15 days including colds, cough, phlegm, nasal congestion, wheezing, rash, vomiting, diarrhoea, fever, nasal secretion, difficulty breathing, and other illness.

While both groups had similar numbers of illnesses, the infants whose mothers had taken DHA had reduced symptom duration at 1 month compared to the placebo group. At 1 month, the DHA group experienced a 26%, 15% and 30% significantly shorter duration of cough, phlegm and wheezing, respectively, but 22% longer duration of rash. At month 3, infants in the DHA group were ill 14% less of the time compared to those in the placebo group. At 6 months, infants in the DHA group experienced 20%, 13%, 54%, 23% and 25% shorter duration of fever, nasal secretion, difficulty breathing, rash and other illness respectively, but 74% longer duration of vomiting.

To date, only one other randomized, placebo- controlled trial has specifically addressed the impact of Omega-3 LC-PUFA supplementation on infant immunity2,3, 4. That study included atopic women provided with fish oil rather than algal sourced DHA. It showed that fish oil changed some aspects of infants immune function and lowered the risk of specific allergies as assessed by skin prick test. It also modified maternal breast milk composition such that it might enhance infant immune response. The Emory University study extended those results to show the clinical response of those alterations in infant immune function.

Previous studies have reported other benefits of omega-3 LC-PUFAs during pregnancy and/or while breast feeding on the infant and toddler. Two studies published earlier this year showed that higher dietary intake of DHA during pregnancy improved memory in 11 year old children,5 while DHA supplementation during pregnancy enhanced brain function in children just entering school (approximately age 5 years).6 Others have reported higher maternal DHA status at birth is associated with enhanced attentional functioning in toddlers during their first and second years of life9,10 while higher DHA concentration in umbilical cord blood (a good indicator of foetal exposure to that nutrient during the last trimester of pregnancy) and higher DHA concentration in infant cord blood increases gestation, improves visual acuity and intelligence at 6 months of age, and also increases mental and psychomotor development at 11 months of age11. A trial including term infants showed the quality of movement was dependent on how high the infants DHA was at the time of birth and was independent of gender, cognitive performance, gestational age and age at measurement12. Earlier in 2007, a similarly designed study showed that low infant blood levels of DHA predict the development of internalizing problem behaviour later in life13. A 2009 study reported that babies born to mothers who took DHA during pregnancy and while breast feeding are 7.5 times less likely to develop food allergies and 3 times less likely to develop eczema.8 A study published in early 2011 reported that babies born to mothers who eat the recommended quantity of DHA during pregnancy are 32 percent less likely to have excessive body fat indicative of potential obesity7. The largest clinical study ever providing DHA to 2,399 pregnant women, reported a 60% reduction in slow developing cognitive and language skills in infants, a 35% reduction in the incidence of low birth weight babies and 50% reduction in the number of very early pre-term deliveries with no serious adverse effects for either the mother or infant15.

Other clinical studies have shown that maternal fish intake during pregnancy is associated with higher IQ in offspring14, and that pregnant mothers taking DHA rich fish oil supplements during the last trimester can maintain their DHA status.16 In addition, infants born to these mothers have also been shown to start life with higher DHA levels than those of mothers who were not supplemented.16 Infants with higher DHA status have enhanced sleep patterns suggesting greater central nervous system maturity17, enhanced attention and mental processing10, score better in mental processing tests18, have higher IQs at four years of age19 and higher scores for language comprehension, average phrase length and vocabulary20.

The Emory University study adds to the massive body of information supporting the need for and importance of DHA supplementation for the health of future generations. This study group is now turning age 4, and at age 5 the researchers plan to study their school performance and other long-term effects aimed at confirming if children grow better and are smarter following maternal supplementation during pregnancy.